The present invention relates to a feedthrough seal apparatus, system, and, method, and more specifically relates to a capacitor feedthrough seal apparatus, system, and method.
In some instances, high voltage capacitors are used for implantable medical device applications. Capacitors paired with batteries can provide high-energy power solutions for various devices, such as, for instance, tachycardia devices. In some instances, the energy is delivered in the form of electrical current by a lead wire that originates at the anode in the capacitor and reaches out of the capacitor into the device. For the proper transfer of energy a seal is needed through which the lead wire can reach to the outside of the component. There are two primary functions of the seal: (1) to inhibit electrical conduction between the case and the wire; and (2) to inhibit material transfer from inside the capacitor into the device.
Typically, a feedthrough seal includes glass, which is melted and solidified between the inside of a ferrule and a concentrically placed tantalum wire. Such an assembly is known as a glass-to-metal seal (GTMS). The GTMS is prepared separately around the tantalum wire. A second tantalum wire from a formed anode assembly is cut to size, bead blasted to remove oxide layer, and then welded onto the tantalum wire coming from the GTMS. The anode and GTMS assembly then undergo a reforming step by heating. The ferrule of the GTMS is then laser welded to the capacitor case. Thus, the entire sealing procedure involves a number of steps making it a complex, expensive, and time-consuming process.